Even though children are filthy, virus-carrying monsters, parents are significantly less likely to get the common cold than those without kids.

A recent Carnegie Mellon University study says that parents are actually half as likely to catch a cold than non-parents — and that number gets higher with each additional kid. Apparently this has nothing to do with immunity from built up exposure to the cold virus either.

The study tested 800 adults by giving them drops containing cold viruses. Researchers controlled for immunity to make sure that this wasn't just a case of parents being around viruses more often.

According to the research, parents were 52 percent less likely to contract the cold. But wait, parents who didn't live with their children were 73 percent less likely — which means the best way to stay healthy is probably to have kids and then ship them off to boarding school.

The study's author Sheldon Cohen could not explain the resistance, except to reiterate that it's not immunity-based.

Although parenthood was clearly protective, we were unable to identify an explanation for this association. Because we controlled for immunity to the virus, we know that these differences did not occur just because the parents were more likely to have been exposed to the virus through their children.

Perhaps there is a psychological imperative to stay healthy in order to protect one's children, though that does seem distinctly unfair to those of us who just want to protect ourselves.

On the other hand, being a parent makes you 100 percent more likely to have kids, which can be a disadvantage in plenty of other ways.